This invention relates to the switching of light between optical components, and more specifically to an optical switch for providing such switching.
Optical switches of various kinds are well known for selectably switching light from one optical fiber or light-conducting path to another. One such switch is disclosed by Pan in U.S. Pat. No. 5,999,669 issued Dec. 7, 1999, which is incorporated herein by reference. Although this invention appears to adequately perform its intended function, it is believed to be costly to manufacture. For example, Pan""s 1xc3x972 switch requires three collimating lenses to input/output fibers to collimate and focus light received from input fibers and destined for output fibers respectively. Furthermore, Pan provides a two-sided switch wherein optical fibres extend from opposite ends of the switch to allow light to be switched from an input optical fibre on one end with two different output optical fibres at another end. Two-sided switches have proven successful for switching optical signals but remain bulky for packaging into devices requiring such switching. Furthermore two-sided optical switches are more costly to hermetically seal than a single-sided switch.
It is therefore an object of the invention to provide a more compact single-sided device providing similar functionality but requiring less space than a two-sided switch.
It is an object of the invention to provide a single-sided optical switch that obviates some of the disadvantages associated with two-sided prior art devices.
It is an object of this invention to provide an optical switch requiring fewer lenses than ports.
In accordance with the invention there is provided, an optical switch, comprising:
a plurality of ports for transmitting and receiving a beam of light;
a stationary reflector for receiving the beam of light from the at least one of the plurality of ports and for substantially reflecting at least a portion of the beam of light to an other of the plurality of ports;
a lens disposed between the plurality of ports and the stationary reflector for substantially collimating the beam of light from at least one of the plurality of ports at the stationary reflector and for substantially focussing the beam of light about the plurality of ports;
a moveable refractor selectably positionable between at least one of the plurality of ports and the stationary reflector, for switching the beam of light from one of the plurality of ports to an other of the plurality of ports via the lens and the stationary reflector.
An embodiment of the present invention provides one-sided switching through the use of a moveable refractor and a stationary mirror. Switching is effected by repositioning the refractor so as to redirect light from one output port to another. The use of a moveable refracting component is advantageous because the refracting component can be aligned with a relatively high degree of tolerance to small misalignment caused by unwanted vibration, which would affect moveable components more than fixed ones in a switching device. This is opposed to using a moveable mirror as the switching element, which is more sensitive to misalignment than a refracting component.
Advantageously, the switch, in accordance with this invention, can be configured to provide a switching device whereby two beams of light transmitted from a first and a second input port are switchable from two output ports to provide controlled feedback, or as a 1xc3x972 switch by allowing a beam of light transmitted from a first port to be switched between output ports. Finally, having the optical fibres enter and leave on the same side makes the device more compact, while having fewer lenses than ports reduces the cost of fabricating and indeed reduces the space required to contain such a device.